chromeos: Refactor shelf to create ShelfView earlier in startup

chrome/browser/chromeos/accessibility/chromevox_panel.cc

Index: chrome/browser/chromeos/accessibility/chromevox_panel.cc
diff --git a/chrome/browser/chromeos/accessibility/chromevox_panel.cc b/chrome/browser/chromeos/accessibility/chromevox_panel.cc
index dc5be1dee8d048c61ea76aa296c97d24b631fcac..0dd1b6c5f30ae4b3afdaa750280aff72ff59173c 100644
--- a/chrome/browser/chromeos/accessibility/chromevox_panel.cc
+++ b/chrome/browser/chromeos/accessibility/chromevox_panel.cc
@@ -132,14 +132,11 @@ void ChromeVoxPanel::DidFirstVisuallyNonEmptyPaint() {
 }
 
 void ChromeVoxPanel::UpdatePanelHeight() {
-  ash::WmShelf* shelf =
-      ash::WmShelf::ForWindow(ash::WmWindow::Get(GetRootWindow()));
-  if (!shelf->IsShelfInitialized())
-    return;
+  SendPanelHeightToAsh(kPanelHeight);
+}
 
-  ash::ShelfLayoutManager* shelf_layout_manager = shelf->shelf_layout_manager();
-  if (shelf_layout_manager)
-    shelf_layout_manager->SetChromeVoxPanelHeight(kPanelHeight);
+void ChromeVoxPanel::ResetPanelHeight() {
+  SendPanelHeightToAsh(0);
 }
 
 void ChromeVoxPanel::EnterFullscreen() {
@@ -202,3 +199,17 @@ void ChromeVoxPanel::UpdateWidgetBounds() {
 
   widget_->SetBounds(bounds);
 }
+
+void ChromeVoxPanel::SendPanelHeightToAsh(int panel_height) {
+  // WmShelf is available for the lifetime of the RootWindowController.
+  ash::RootWindowController* root_window_controller =
+      ash::RootWindowController::ForWindow(GetRootWindow());
+  if (!root_window_controller)
+    return;
+
+  // TODO(mash): Replace with shelf mojo API.
+  ash::ShelfLayoutManager* shelf_layout_manager =
+      root_window_controller->GetShelf()->shelf_layout_manager();
+  if (shelf_layout_manager)
+    shelf_layout_manager->SetChromeVoxPanelHeight(panel_height);
+}